(1) Field of the Invention
This invention relates to an apparatus for preparing large quantities of vaccine for mammals, and to the process for employing the substantially evacuated red blood cells of said mammals, thus providing a means of utilizing the erythrocytes in the vaccination of these animals.
(2) Description of the Prior Art
G. M. Ihler, et al. in Proceedings of the National Academy of Science of the U.S.A., Volume 70, pp 2663-2666 (1973), used a large hypotonic dilution to encapsulate enzymes with a maximum encapsulation less than 1%. Later a one-third to one-fifth hypotonic dilution was used to encapsulate the enzyme uricase. In 1976 and 1977 other variations on the hypotonic dilution method have been used for other animal erythrocytes (see E. Ang., et al., Experimental Cell Research, Volume 104, pp 430-434). Another method of encapsulation of substances in erythrocytes employs electrochemical shock [see F. Riemann, et al., Biochimica et Biophysica Acta, Volume 394, pp 449-462 (1975)]; however, this method requires sophisticated equipment to generate exponentially decaying electric fields.
J. R. DeLoach, et al. reported in 1977 a dialysis method for encapsulating enzymes and lipids in erythrocytes, where up to 45% of the added substances could be encapsulated. In that procedure, human erythrocytes at 70% to 80% hematocryt were dialyzed against 1 to 2 liters of distilled water for 2 hours. At 5 to 10 minute intervals the dialysis bag was removed and its contents mixed. Sufficient homogeneous mixing was not achieved and it was difficult to prepare large quantities of resealed erythrocytes.
The prior art also discloses the use of dialysis to encapsulate enzymes with a maximum of about 30% encapsulated (see G. L. Dale, et al., Biochemical Medicine, Volume 18, pp 220-225, 1977). More recently, M. Yamaiuzimi, et al., in Cell, Volume 15, p 245 (1978) employed a dialysis procedure for encapsulation of Immunoglobulin G (IgG) in erythrocyte ghosts. Although these authors reported the IgG concentrations inside the erythrocyte ghosts, no report on percent uptake was made.
The reports of the prior art indicate that there is yet much to be done to advance the state of the art. The present invention provides a step in that direction.
(3) Definitions Applicable To This Invention
Resealed erythrocytes--These are red blood cells that have been swelled to the extent that pores open in their membrane, then are restored to isotonic condition and annealed. They are unlike white ghosts in that they retain about from 50% to 70% of their soluble cellular components.
Erythrocyte ghosts--This term is sometimes employed as synonymous with resealed erythrocytes.
Isotonic--This term is used to describe a solution whose osmotic pressure is about the same as normal mammalian blood.
Hypotonic--This term is used to describe a solution whose osmotic pressure is less than osmotic pressure of mammalian blood.
Osmolality--The molality of an ideal solution that exerts the same osmotic pressure as the solution being considered.
Additive--Any substance which may be combined with erythrocytes for the purpose of encapsulation.
Exogenous substance--This term is employed synonymous with additive.